The Journal of Medical Microbiology, Vol 42, Issue 3 225-229, Copyright © 1995 by Society for General Microbiology
Non-opsonic phagocytosis of Trichophyton mentagrophytes arthroconidia by human neutrophils in vitro
M. D. Richardson and Y. Bell
Department of Dermatology, University of Glasgow.
A non-opsonic mechanism of binding and phagocytosis by human neutrophils of
Trichophyton mentagrophytes arthroconidia is described. This was in direct
contrast to the complement dependency of Candida albicans phagocytosis.
Both serum complement and specific antibody to T. mentagrophytes promoted
maximal phagocytosis (61% and 40% of neutrophils, respectively, contained
arthroconidia). Increasing the ratio of arthroconidia to neutrophils did
not increase non-opsonic phagocytosis (18-26%). Phagocytosis of
arthroconidia exposed to trypsin in the absence of opsonin was not affected
(18%). However, proteinase and chitinase reduced the level of non-opsonic
and opsonic phagocytosis to negligible levels (6.3% and 4.5%,
respectively). When mannose was added to neutrophils, mannose receptors on
the phagocyte membrane were partially blocked when arthroconidia were
opsonised, but this did not reduce the level of non-opsonic phagocytosis.
The non-opsonic mechanism proposed here may have direct relevance in skin
sites poor in opsonins.
